Reverse flow vacuum system

ABSTRACT

A vacuum uses reverse pulses from the vacuum motor to clean the filter associated therewith. Vacuum filters may be cleaned quickly and efficiently without expelling collected debris from the vacuum. Vacuums with two motors may be operated from 220 or 110 volt sources without a loss of power.

PRIORITY

The present application claims the benefit of U.S. Provisional Application Ser. No. 61/399,853, filed Jul. 19, 2010, which is herein incorporated by reference in its entirety.

THE FIELD OF THE INVENTION

The present invention relates to vacuums. More specifically, the present invention relates to a reverse flow system for preventing a vacuum filter from becoming clogged, allowing the vacuum to operate more effectively.

BACKGROUND

It is important for vacuum systems to provide effective filtration. In construction and commercial applications, vacuums are often used to collect debris which is generated while using a cutting tool. Very fine particulate filters are used to collect the dust and prevent the health hazards associated with breathing fine dust. The vacuum filters become clogged as they collect the dust from the air. This reduces the vacuums ability to collect dust and air flow is reduced. For this reason, significant effort has been directed towards keeping vacuums from clogging and extending the time between cleaning or changing a filter.

Various attempts have been made to unclog vacuum filters. A known prior art device uses a compressed air reverse pulse system that uses an on board air compressor to pulse compressed air into a port connected to the interior (low pressure side) of the vacuum filter in order to briefly reverse the airflow through the filter. The air pulse must overcome the airflow of the vacuum motor. This reverse pulse becomes less effective for vacuum systems that have relatively high amounts of airflow and create a high degree of suction. In this case, the filter does not release the debris that has collected on the surface of the filter media very well because the reverse pulse of air is insufficient to overcome the air flow that the vacuum motor is creating.

Another drawback of this system is the requirement for compressed air. These systems include an air compressor and air tank creating and storing compressed air at about 90 psi. A dump valve periodically releases a sudden blast of air from the tank and vents the air blast into the clean side of the vacuum filter. This air blast blows the dust off of the outside of the filter. This adds additional weight, size and complexity to the system. The additional weight and size are particularly disadvantageous for portable systems. The added complexity typically causes increased repairs and a higher cost of maintenance.

There is a need for a system to keep a vacuum filter clean and functioning properly. There is particularly a need for a system which effectively cleans a vacuum filter without adding to the size of the vacuum or becoming overly complicated. There is a need for a system which is effective in all sizes of vacuums and is useful in both smaller vacuums as well as large commercial vacuums.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improved system for cleaning vacuum filters.

According to one aspect of the invention, a system if provided which uses the air flow from the vacuum motor itself to unclog the vacuum filter. Airflow from the vacuum motor is reversed through the filter to unclog the filter. According to another aspect of the invention, a valve is used to reverse the vacuum motor airflow without stopping or reversing the motor itself. The system allows the filter to be unclogged instantly without placing a high degree of stress on the vacuum motor.

These and other aspects of the present invention are realized in a system for unclogging vacuum filters as shown and described in the following figures and related description.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present invention are shown and described in reference to the numbered drawings wherein:

FIG. 1 shows a schematic view of a vacuum according to the present invention;

FIG. 2 shows another schematic view of the vacuum of FIG. 1;

FIG. 3 shows another schematic view of a vacuum according to the present invention;

FIG. 4 shows another schematic view of the vacuum of FIG. 3;

FIG. 5 shows a valve according to the present invention;

FIG. 6 shows another schematic view of a vacuum according to the present invention;

FIG. 7 shows a vacuum control panel according to the present invention; and

FIG. 8 shows a schematic view of the control panel of FIG. 7.

It will be appreciated that the drawings are illustrative and not limiting of the scope of the invention which is defined by the appended claims. The embodiments shown accomplish various aspects and objects of the invention. It is appreciated that it is not possible to clearly show each element and aspect of the invention in a single figure, and as such, multiple figures are presented to separately illustrate the various details of the invention in greater clarity. Similarly, not every embodiment need accomplish all advantages of the present invention.

DETAILED DESCRIPTION

The invention and accompanying drawings will now be discussed in reference to the numerals provided therein so as to enable one skilled in the art to practice the present invention. The drawings and descriptions are exemplary of various aspects of the invention and are not intended to narrow the scope of the appended claims.

Turning now to FIGS. 1 and 2, schematic views of a vacuum according to the present invention are shown. Many parts of the vacuum are not shown, as they do not pertain to the present system. The vacuum includes a vacuum motor 10, a vacuum filter 14 and a debris canister 18. A vacuum suction hose 22 or pre-filter 24 such as a cyclone filter is typically connected to an air inlet 26 associated with the debris canister 18. Where a pre-filter 24 is used, a suction hose 22 is often connected to the inlet side of the pre-filter. The suction hose 22 is typically used to manually collect dust and debris, or in many cases, the hose is connected to a machine tool such as a grinder to collect the debris made by the machine tool. Dust and debris flows into the debris canister and is separated from the air by the filter 14. In operation, much of the fine dust and debris is trapped on the surface of the filter 14. This dust and debris increases the pressure required to flow air through the filter and decreases the air flow through the filter. Correspondingly, the vacuum is less able to collect dust and debris.

A valve body or valve manifold 30 is used to control air flow between the vacuum motor 10 and the filter 14. The valve 30 has two ports on the motor side of the valve. A first port 34 is connected to the motor inlet 38 via a conduit 42. A second port 46 is connected to the motor exhaust outlet 50 via a conduit 54. On the filter side of the valve 30, a port 58 is connected to the filter 14 via a conduit 62. A second port or an opening, indicated at 66, is open to the atmosphere. As shown in FIG. 1, when the valve 30 is in a first, normal operating position air is drawn through the filter 14, through the motor 10 and is exhausted into the atmosphere.

As shown in FIG. 2, the valve 30 may be moved to a second, cleaning position. In this position, the port 58 and conduit 62 are placed in communication with the motor exhaust conduit 54 and the motor inlet is connected to the atmosphere as indicated at 70. In this position, air is drawn through the motor from the atmosphere and is pushed into the filter, the airflow through the filter being reversed compared to normal operation of the vacuum. Debris 74 is expelled from the surface of the filter 14 and collected in the debris canister 18. The airflow need only be reversed as shown in FIG. 2 for a brief moment to clean debris from the filter 14 as the motor 10 is powerful and as the reverse airflow does not fight any conventional airflow through the vacuum.

FIGS. 3 and 4 show a similar arrangement to FIGS. 1 and 2. FIGS. 3 and 4 differ from FIGS. 1 and 2 in that the motor is enclosed in a chamber 78. The valve 30 is attached to the chamber wall as shown. In this configuration, the motor exhaust outlet 50 need not be connected directly to the valve port 46. The motor chamber 78 is enclosed other than the valve 30 and the exhaust air flows out through port 46, as indicated at opening 66. The motor chamber 78 serves as a muffler for the motor 10 and significantly reduces the vacuum noise. FIG. 3 shows the valve 30 in a first, normal operating position where debris laden air is drawn through the vacuum filter 14 into the interior of the filter, through the motor 10 and is exhausted to the atmosphere. FIG. 4 shows the valve in a second, cleaning position where fresh air is drawn from the atmosphere, through the motor and is pushed into the interior of the filter 14, reversing air flow through the filter and removing debris 74 from the filter.

FIG. 5 shows an exemplary valve 30. The valve 30 has ports 34, 46 and 58 as described above, and can selectively open one of the motor ports 34, 46 to the atmosphere as indicated at 66. The filter port 58 is attached to a plate 82 which is held captive in channels 86. The plate can slide from the first position (shown) where the port is connected to motor port 34 to a second position where the port 58 is pneumatically coupled to motor port 46, selectively opening the other of port 34 and 46 to the atmosphere. In this manner, the valve 30 reverses the flow of air through the filter 14 without stopping or reversing the motor 10. The plate 82 is typically biased into the first position with a spring and is operatively connected to a lever on the control panel vacuum via a coupling.

A user moves the lever to thereby move the plate 82 and reverse the flow through the filter for cleaning. Upon releasing the lever, the plate 82 is moved automatically back into the first position shown for conventional operation of the vacuum. The present system cleans the filter 14 well with only a very short duration of reverse flow because the full power of the motor is used to clean the filter. Thus, a user will typically move the valve control lever to reverse the flow and immediately release the lever to allow the vacuum to return to normal operation. This brief reversal of flow does not cause the vacuum to push debris back out of the filter canister air inlet 26. It will be appreciated that the valve 30 may be automatically operated as well.

FIG. 6 shows a vacuum configuration having two motors 10, two filters 14, and two sets of valves 30 and associated conduits. For clarity, not all structures are numbered. Except as discussed to the contrary, each motor 10, valve 30 and filter 14 operates as discussed with respect to FIGS. 1 and 2. The two filters 14 are both disposed in a single debris canister 18 and both draw air through a single air inlet 26. The vacuum has double the power and air flow as the conventional vacuum of FIG. 1.

This two motor system is advantageously combined with the present reverse flow system. In cleaning the vacuum filters 14, a single valve 30 is operated at a time to reverse the flow through only a single filter 14. In this situation, one motor 10 is blowing air through a filter 14 and into the debris canister 18 while the other motor 10 draws air from the other filter and out of the debris canister. This results in a near zero flow into or out of the debris canister through inlet 26 and eliminates the risk of blowing debris out of the vacuum while cleaning the filters 14. One filter 14 is thus quickly cleaned as discussed above and the second filter 14 is then cleaned afterwards.

FIG. 7 shows an electrical power system of the present invention used to power a vacuum with two motors 10 off of either 110 or 220 volts without a loss of power when using a 110 volt power source. It is appreciated that a 110 volt line is typically limited to 12 amps of power draw, and thus devices operating from 110 volts typically have less power than 220 volt devices. The vacuum uses an internal power panel 90 which distributes power to two vacuum motors 10. A 220 volt plug 94 and cord 98 extends from the power panel 90 and is connected to a 220 volt source. The power panel 90 houses two 110 volt receptacles 102. Internal to the power panel 90, the 220 volt feed is separated into two 110 volt sources and connected to the two receptacles 102, as is shown in FIG. 8. Each motor 10 has a 110 volt power cord 106 and plug 110.

During normal operation, the two 110 volt plugs 110 are connected to the 110 volt receptacles 102 and the 220 volt plug 94 is connected to a 220 volt supply. Two switches may be disposed between the 110 volt plugs 110 and the motors 10 to turn the motors on or off. Alternatively, a single switch may be disposed on the vacuum to control both motors. When a 220 volt supply is not available, the two motor plugs 110 are removed from the receptacles 102, plugged into separate extension cords, and the two extension cords are plugged into separate 110 volt circuits of the house or location where work is being performed. This allows each motor to individually draw the maximum current available from a 110 volt source and allows the vacuum to operate at a high power level on a 110 volt source rather than a reduced power level.

There is thus disclosed an improved vacuum. The vacuum system allows for quick and efficient cleaning of the vacuum filters while avoiding practices which are harmful to the vacuum filters and motors. Additionally, the vacuum It will be appreciated that numerous changes may be made to the present invention without departing from the scope of the claims. 

1. A vacuum comprising: a vacuum motor having an inlet and an outlet; a filter a valve manifold, the valve manifold having: a first port fluidly connected to the vacuum motor inlet; a second port fluidly connected to the vacuum motor outlet; a third port fluidly connected to the vacuum filter; and wherein the valve manifold is movable between a first position and a second position, the first position placing the third port in communication with the first port such that the motor draws air through the filter to create suction in the filter, the second position placing the third port in communication with the second port such that the motor blows air through the filter to create pressure in the filter.
 2. The vacuum of claim 1, wherein, in the first position the second port is in communication with the atmosphere.
 3. The vacuum of claim 1, wherein, in the second position the first port is in communication with the atmosphere.
 4. The vacuum of claim 1, wherein the filter is disposed in a debris canister, and wherein the debris canister has an inlet for collecting debris.
 5. The vacuum of claim 1, further comprising: a second vacuum motor having an inlet and an outlet; a second filter a second valve manifold, the valve manifold having: a first port fluidly connected to the vacuum motor inlet; a second port fluidly connected to the vacuum motor outlet; a third port fluidly connected to the vacuum filter; and wherein the valve manifold is movable between a first position and a second position, the first position placing the third port in communication with the first port such that the motor draws air through the filter to create suction in the filter, the second position placing the third port in communication with the second port such that the motor blows air through the filter to create pressure in the filter.
 6. The vacuum of claim 5, wherein the vacuum comprises: a 220 volt cord for receiving power from a 220 volt outlet; a power panel; two 110 volt outlets disposed in the power panel, the two 110 volt outlets being connected to the 220 volt cord to receive 110 volt power therefrom; and two 110 volt power cords connected to the first vacuum motor and the second vacuum motor.
 7. The vacuum of claim 1, wherein the valve manifold is biased into the first position.
 8. The vacuum of claim 1, further comprising a lever operatively connected to the valve manifold for moving the valve manifold between the first position and the second position.
 9. A vacuum comprising: a vacuum motor having an inlet and an outlet; a filter; a valve manifold, the valve manifold being movable between a first position wherein the filter is fluidly connected to the vacuum motor inlet to create suction in the filter and a second position wherein the filter is fluidly connected to the vacuum motor outlet to create pressure therein.
 10. The vacuum of claim 9, the valve manifold having: a first port fluidly connected to the vacuum motor inlet; a second port fluidly connected to the vacuum motor outlet; a third port fluidly connected to the vacuum filter.
 11. The vacuum of claim 9, wherein the valve manifold is biased into the first position.
 12. The vacuum of claim 9, further comprising a lever connected to the valve manifold, the lever being movable to move the valve manifold into the second position.
 13. The vacuum of claim 9, further comprising: a second vacuum motor having an inlet and an outlet; a second filter: a second valve manifold, the valve manifold being movable between a first position wherein the filter is fluidly connected to the vacuum motor inlet to create suction in the filter and a second position wherein the filter is fluidly connected to the vacuum motor outlet to create pressure therein.
 14. The vacuum of claim 13, further comprising a debris canister, and wherein the first filter and the second filter are disposed in the debris canister.
 15. The vacuum of claim 13, further comprising: a 220 volt inlet cord; a power panel having two 110 volt receptacles, the 220 volt cord being connected to the two 110 volt receptacles to provide 110 volts to each receptacle; a first 110 volt power cord connected to the first vacuum motors and connected to the first 110 volt receptacle; and a second 110 volt power cord connected to the second vacuum motors and connected to the second 110 volt receptacle.
 16. A vacuum comprising: a first 110 volt vacuum motor; a first 110 volt power cord connected to the first vacuum motor; a second 110 volt vacuum motor; a second 110 volt power cord connected to the second vacuum motor; a power panel having a first 110 volt receptacle and a second 110 volt receptacle, the first 110 volt cord being removably connected to the first 110 volt receptacle, the second 110 volt cord being removably connected to the second 110 volt receptacle; and a 220 volt power cord connectable to a 220 volt receptacle to draw power therefrom and connected to the first and second 110 volt receptacles to provide 110 volts thereto.
 17. The vacuum of claim 16, further comprising a first filter fluidly connected to the first vacuum motor and a second filter operatively connected to the second vacuum motor, the first and second filters being disposed in a single debris canister. 